When creating a backup of a world, if that world is sufficiently large, the game will stop responding during the backup process.
To reproduce
Generate a world
Generate a very large amount of chunks in that world, enough that the world's backup size is around 400 to 500 MB or higher
In the world selection screen, choose that world, select EDIT, and select BACKUP.
→ ❌ The game will stop responding, or "hang", until the backup is finished.
Comments 4
Can confirm; I have my 450+ MB world on my HDD, that's probably the best way to reproduce; I imagine this issue does not happen if the world is on a SSD.
This may be considered to be a duplicate of MC-134573.
In my experience, larger worlds do backup, but can take several minutes to do so.